What happens when test tube babies are left in the tube to grow?

I was just reading a book and they mentioned in the book something about the first experiments in the 60's where they were trying to accomplish in vitro fertilization. It said that the scientists were able to start babies, actual human fetuses, in test tubes, and for a while they developed normally outside the mother. Then, their development would start going awry and they became severely deformed. Is this actually true? If so, why does this happen? Can anybody find some good websites with information about this? [So far, I've had no luck.] Thanks!